“We are deeply saddened by the information coming out of two former residential boarding school sites in Canada,” Chieko Noguchi, the spokesperson of the U.S. Conference of Catholic Bishops, said.

The discovery that follows last month's report of 215 bodies found at another school.

Two Roman Catholic churches on First Nations reserves in British Columbia have burned to the ground in overnight fires, Canada’s national police force said Monday.

“The fundamental reality of children dying at these boarding schools is not a new story.”

The discovery of the unmarked graves of First Nations' children led to renewed calls for a papal apology in Canada to respond to the legacy of residential schools and revived questions about the church’s role in colonialism in Canada.

“Canadian political and religious authorities may continue to cooperate with determination to shed light on that sad situation and to commit themselves humbly to a path of reconciliation and healing,” Pope Francis said.